clone: support unusual remote ref configurations

When cloning a branchless and tagless but not refless remote using
protocol v0 or v1, Git calls transport_fetch_refs() with an empty ref
list. This makes the clone fail with the message "remote transport
reported error".

Git should have refrained from calling transport_fetch_refs(), just like
it does in the case that the remote is refless. Therefore, teach Git to
do this.

In protocol v2, this does not happen because the client passes
ref-prefix arguments that filter out non-branches and non-tags in the
ref advertisement, making the remote appear empty.

Note that this bug concerns logic in builtin/clone.c and only affects
cloning, not fetching.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jonathan Tan 2022-01-24 10:09:09 -08:00 committed by Junio C Hamano
parent e9d7761bb9
commit dccea605b6
2 changed files with 21 additions and 6 deletions

View File

@ -862,7 +862,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
const struct ref *refs, *remote_head;
struct ref *remote_head_points_at = NULL;
const struct ref *our_head_points_at;
struct ref *mapped_refs;
struct ref *mapped_refs = NULL;
const struct ref *ref;
struct strbuf key = STRBUF_INIT;
struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
@ -1184,7 +1184,10 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
refs = transport_get_remote_refs(transport, &transport_ls_refs_options);
if (refs) {
if (refs)
mapped_refs = wanted_peer_refs(refs, &remote->fetch);
if (mapped_refs) {
int hash_algo = hash_algo_by_ptr(transport_get_hash_algo(transport));
/*
@ -1193,8 +1196,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
*/
initialize_repository_version(hash_algo, 1);
repo_set_hash_algo(the_repository, hash_algo);
mapped_refs = wanted_peer_refs(refs, &remote->fetch);
/*
* transport_get_remote_refs() may return refs with null sha-1
* in mapped_refs (see struct transport->get_refs_list
@ -1240,7 +1241,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
option_branch, remote_name);
warning(_("You appear to have cloned an empty repository."));
mapped_refs = NULL;
our_head_points_at = NULL;
remote_head_points_at = NULL;
remote_head = NULL;
@ -1271,7 +1271,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
if (is_local)
clone_local(path, git_dir);
else if (refs && complete_refs_before_fetch) {
else if (mapped_refs && complete_refs_before_fetch) {
if (transport_fetch_refs(transport, mapped_refs))
die(_("remote transport reported error"));
}

View File

@ -149,6 +149,21 @@ test_expect_success 'push with file:// using protocol v1' '
grep "push< version 1" log
'
test_expect_success 'cloning branchless tagless but not refless remote' '
rm -rf server client &&
git -c init.defaultbranch=main init server &&
echo foo >server/foo.txt &&
git -C server add foo.txt &&
git -C server commit -m "message" &&
git -C server update-ref refs/notbranch/alsonottag HEAD &&
git -C server checkout --detach &&
git -C server branch -D main &&
git -C server symbolic-ref HEAD refs/heads/nonexistentbranch &&
git -c protocol.version=1 clone "file://$(pwd)/server" client
'
# Test protocol v1 with 'ssh://' transport
#
test_expect_success 'setup ssh wrapper' '